SPI driver for Atmel DataFlash

[togrady]

Posted on March 06, 2008 at 20:18

SPI driver for Atmel DataFlash

[lanchon]

Posted on May 17, 2011 at 12:25

and here's another forum bug:

type &lt;PRE&gt; and hit preview, it gets converted to <PRE>... ugly!

[togrady]

Posted on May 17, 2011 at 12:25

#define DUMMY_BYTE 0xff

static unsigned char tx8(unsigned char data)

{

while ((SPI1->SR & SPI_FLAG_TXE) == (u16)RESET); // Loop while DR register in not emplty

SPI1->DR = data;

while ((SPI1->SR & SPI_FLAG_RXNE) == (u16)RESET); // Wait to receive a byte

return SPI1->DR;

}

void spi_tx_8 (unsigned char _data8)

{

tx8(_data8);

}

unsigned char spi_rx_8 (void)

{

return tx8(DUMMY_BYTE);

}

unsigned long spi_rx_32 (void)

{

unsigned long r;

int i;

for (i = 0,r = 0; i

{

r |= spi_rx_8();

if (i

r<<=8;

}

return r;

}

void spi_init (void)

{

SPI_InitTypeDef SPI_InitStructure;

GPIO_InitTypeDef GPIO_InitStructure;

/* Enable SPI1 and GPIOA clocks */

RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1 | RCC_APB2Periph_GPIOA, ENABLE);

/* Configure SPI1 pins: SCK(PA5), MISO(PA6) and MOSI(PA7) */

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;

GPIO_Init(GPIOA, &GPIO_InitStructure);

/* Configure PA.3 as Output push-pull, used as Flash Chip select */

/********* using pc.6 (LED1)

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;

GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;

GPIO_Init(GPIOA, &GPIO_InitStructure);

*/

/* Deselect the FLASH: Chip Select high */

DATAFLASH_CS_HI();

/* SPI1 configuration */

SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;

SPI_InitStructure.SPI_Mode = SPI_Mode_Master;

SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;

SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;

SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;

SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;

// SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_4;

SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_16;

SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;

SPI_InitStructure.SPI_CRCPolynomial = 7;

SPI_Init(SPI1, &SPI_InitStructure);

/* Enable SPI1 */

SPI_Cmd(SPI1, ENABLE);

}